Apparatus for recovering precious metals.



F. A WISWELL. APPARATUS FOR RECOVERING PRECIOUS METALS.

APPLICATION FILED FEB 11, 1914. 1,120,637. Patented Dec. 8, 1914.

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EA. W'z'swell F. A. WISWELL. APPARATUS FOR RBCOVERING PRECIOUS METALS. APPLICATION FILED FEB 11,1914.

1,120,637. Patented Dec. 8, 1914.

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F. A. WISWBLL.

APPARATUS FOR macovsnms PRECIOUS METALS.

APPLICATION FILED L'EB 11,1914.

1, 1 20,637, Patented Dec. 8, 1914.

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F. A. WISWELL.

APPARATUS FOR RECOVBRING PRECIOUS METALS.

APPLICATION FILED FEB 11,1914.

1 1 20,637. Patented Dec. 8, 1914..

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flttorrleg FREDERICK A. WISWELL, OF OAKLAND, CALIFORNIA.

APPARATUS FOR RECOVERINiZrl'ERECIOUS METALS.

To all whom it ma concern Be it known t at I, FREDERICK A. WIsmetallic mercury or both, with or without the aid of an externally obtained electric current.

An important object of the invention is to provide apparatus by' the em loyment of which my process described an claimed 1n my copending application filed February 11, 1914, Serial No. 818,06l, may be advanv tageously practised.

Other objects and advantages of the invention will be a parent during the course of the following escription.

In the accompanying drawings forming a part of this specification and in which, like numerals are employed to designate like parts throughout the same, Figure 1 is a central longitudinal sectional view through the apparatus, taken on line 11 of Fig. 2 Fig. 2 is a plan view of the same, Fig. 3 is a horizontal sectional view taken on line 3-'3 of Fig. 1, Fig. 4 is an elevation of one end of the apparatus, Fig. 5 is a side elevation of the mercury salt 'treatin amalgamator, included in the apparatus, Fig. 6 is a central longitudinal sectional view through he same, Fig. 7 1s a side eleyation of iirotatable drum included in the same, Fig, 8 is a transverse sectional view taken onv line 8---8 of Fig. 7, Fig. 9 is a similar view taken on line 9 -9 of Fig. 6, Fig. 10 is a fra central lo'ngitudinal section taken t rough 'a slightly different form of mercuric salt treating amalgamator, Fig. 11 is a transverse sectional view taken on line 1111 of 10, Fig, 12 is a similar "iew taken on line 12-12 of Fig. 10, and, Fig. 13 is a detail view of ,a contact.

I will first describe the apparatus which may be advantageously employed for carryin out my process.

he numeral 15 desi ates an n standin frame, which may be a vantageou y formed Specification of Letters Patent.

Patented Dec. 8, 1914..

Application filed February 11, 1914. Serial No. 818,065.

of wood or the like. Suitably mounted in the upper portion of the upstanding frame 15 is a mercury salt treating amalgamator, designated as a whole by the numeral 16. This amalgamator, as more clearly shown in Figs. 5, 6, 7 and 8, includes an outer shell 17, which is preferably cylindrical and horizontally arranged. This outer shell is relatively stationary. The outer shell 17 is preferably formed intwo parts 18, provided at their contiguous edges with exterior flanges 19, secured together by bolts 20. Suitable packing may be arranged between these flanges so that the shell will be air tight. The portions 18 of the shell 17 however, are not insulated from each other, but are electrically connected by the bolts 20, for a reason to be apparent hereinafter. The shell 17 or parts thereof is preferably formed of-iron, although other material may be employed. Rotatably mounted within the shell 17 is a cylindrical drum or cylinder 21, which is preferably formed of iron and rigidly mounted upon a driving shaft 22. The drum 21 is provided with radiallyextending teeth 23, arranged in spaced annular groups, the teeth -in each group being spaced, as clearly illustrated in Figs. 7 and 8. The teeth 23 are preferably tapered and decrease in width outwardly. The shell 17 is provided with internally arranged teeth 24, arranged in spaced annular groups, the teeth in each group being spaced. The teeth 2-1 are arranged between the teeth 23, as clearly shown in Fig. 6. Formed upon or connected with the opposite ends of the shell 17 are combined stulling boxes and bearings, including outer'tubular casings 25, which receive therethrough the driving shaft 22. These casings 25 are provided with cham bers for receiving electrical non-conducting packing 26, through which the shaft 22 passes, as shown.

The" numeral 27 designates rings, which engagethe packing 26, and are moved toward the same by clamping bolts 28.

It is desired that the drum 21 be insulated f1 o'm the shell 17, and for this purpose insulating material 29 is interposed between the ends of the drum, shaft 22, and the ends of the shell 17, as more clearly shown in Fig. 6. Insulating material 30 is also interposed between the shaft 22 and the rings 27. As more clearly shown in Fig. 6, the shaft 22 extends axially through the drum 21,1md is rigidly connected therewit y means of transverse pins 29', said drum serving to completely cover and protect the shaft" against chemical action, The drum 21 may be removed when desired. This drum is provided at its ends with tapered orconical heads '31, which decrease in diameter inwardly, serving asguide means for the material being fed into one end of the shell 17 and discharged from the opposite end thereof. Thedrum 21 has an axial bore of sub from the shaft, when desired? :The shell 17 is provided at one end with an enlarged opening, in communication with an inlet pipe 32, carrying a funnel 33 into which a chute 34 discharges, as clearly shown in .Fig. 1. At its opposite'end an outlet pipe 35 leads into the shell 17, such .outlet pipe being provided with a vertical vent pipe 36, serving to prevent the creation of vacuums within the shell 17, whereby the material will freely pass therethrough. The shaft 22 "is rotated by a pulley 37, which is driven from a suitable source of power (not shown). Arranged near and to one side of the funnel 33 is a supply tank 38, for holding and dissolving mercuric chlorid or other ohemi cals, the same being discharged into the funnel 33 through a. spout 39, as clearly illustrated in Fig. 1.

Attention isnow called to Figs. 10, 1-1, and. 12, wherein the shell 17 is shown formed in a single part, with its opposite ends open and closed by plates or heads 40, connected therewith by bolts 41, the heads or plates 40 are thoroughly insulated from the shell 17. The shell 17 is provided with inwardly extending teeth 42, referably'of the sha e shown in F jg, 12.

he drum 21 is of t e same construction as hereinabove described, lrith its teeth 23 operating between the teeth which is insulated from the shell 17 Each plate or head 40 is provided with achamber for receiving electrical non-conducting packmg 43, held'in place by a ring 44, moved inwardly by clamping bolts 45 or the like.

v.The material supply and discharge means connection with one pole of a source ofelec-gfor the drum 21 will remain the same.

Thenumeral 46 desi v v tlculjalrly Figs. 5, 6 an 10), a-wire,having current .(not shown), such wire being ei'ectricallv connected with'the shell 17 by a fbindmgp'ost-M. A wire 48, electrically connected with the opposite .pole; of the source This drum is driven by the shaft 22,

ates, (see more par of current, is connected with suitably supported contact strip or jplate49, (see Fig. 13),having slidable contact with one end of the shaft 22. It is thus seen that the insulated shell 17 and drum 21 are electrically 7 0 connected with the opposite poles of the source of current for apurpose to be hereinafter explained.

. Resting upon the lower portion of the upstanding frame 15 is a stationary upstanding frame 50, upon which is vertically adjustably mounted a supporting frame designated by the numeral 56. The upstanding frame 50 includes four vertical guide standards 51 firmly secured to the frame 50 but slidably fitting intorecessed parts or vertical grooves 56' of the adjustable frame 56, as

shown in Figs. 2 and 3, thus insuring vertical, central alinement of the frames 50 and 56 with each other while admitting of the latter being raised or lowered, which when suitably adjusted, rests on blocks 55 of desired thickness. Within the frame 56 is suitably mounted a horizontal thrust plate 57 and horizontally disposed bearings 58* and 59. Rotatably and centrally mounted within the frame 56 is a vertical tubular-shaft 60, receiving material discharged from the pipe 35. The tubular shaft 60 extends axially within a tank or receptacle 61, which is stationary and suitably connected with the upperend of the frame 50, as shown. Rigidly mounted upon the lower portion of-the tubular shaft 60' and arranged for rotation within the receptacle 61 are suitably spaced superposed agitator blades 62,- which arehorizontally arranged with their upper faces beveled or vertically inclined,whereby they will serve to elevate the ore or material within the receptacle 61, when they are rotated in proper direction. The receptacle 61 is partially filled with .metallic mercury, for a purpose to be explained. Rigidly connected with the upper portion of the tubular shaft 60 is a horizontal bevel gear 63, the

lower end of the hub of which restsonthe horizontal bearing plates 57 and supported thereby. It is thus seen that when the'horizontal frame 56 is elevated the lower end of e the tubular shaft 60 will be moved'away from the lower end of the rece tacle 61, as will be more fully explained Rotatably mounted within the bearings 58 and 59 is a horizontal shaft 64, to the inner end. of

the numeral 67 designates a pulley which is l rotatably mounted upon the shaft and ar- 1251" ranged nearthe pulley 66. It is thus seen that a belt maybe shifted from. the pulleyf 67 to the pulley 66 and vice versa, for r at ing and stopping the shaft 64.

i-The r c tacle 1; provided teaad is);

spaced from its upper end with an outlet pipe 68, which discharges into the vertical tubular shaft 60 of apparatus which is iden tical with the apparatus includin the tubular shaft 60 hereinabove describe ,for which reason it is thought that no further description of the same is necessary, it being understood that any suitable number of these ap paratuses may be connected in tandem or series, as may be found advantageous.

In the use of the apparatus, the preferably sifted sand, gravel or pulverized ores containing fine particles of ,the gold, platinum, silver or the like, preferably having water added thereto to form a mass having a pasty consistency, is fed from the chute 34 to the funnel 33, and passes through pipe 32 into the intake endof the shell 17. An aqueous solution of a salt of mercury, preferably mercuric chlorid, preferably containing a proper amount of sulfuric acid of the desired strength, is fed from the tank 38 into the funnel 33 and passes there-from into the shell 17, to engage with the finely divided precious metal containing material. The shaft 22 is preferably rapidly rotated, to effect a corresponding rotation .of the drum 21, but the speed of rotation of the shaft 22 is to be determined in View of the character of the material being treated. I have found that by adding a proper amount of sulfuric acid of suitable strength to the aqueous solution of mercuric chlorid such mercuric chlorid will not be deteriorated by the sulfuric acid but its chemical action will be aided thereby as will be more fully explained. The aqueous solution of mercuric chlorid in the presence of the iron of the shell 17 gives up to the latter its hydrochloric acid, due to the strong affinity that the hydrochloric acid has for iron, said mercuric chlorid simultaneously precipitating metallic mercury, which under the peculiar conditions present during the reaction, will actively combine with the gold or platinum. The peculiar activity of the metallic mercury thus obtained, to amalgamate the precious metals, is due partly to the fact that electric energy is generated during the operation. The hydrochlorid acid which is formed, as above stated, acts much more readily upon the iron of the shell 17 than ne particles of the precious metals,

acid is added, which is preferred. As a result of this the iron shell 17 and drum 21 become electro-positive, while the precious metals in the menstrum, become electronegative. I have foundthat gold and platinum particles in pulverized ores are ideal substances to fulfil the function of the electro-negative or cathode pole conditions as above explained. The shell 17 and drum 21 are designed and operate to violently agitate 66 the finely divided precious metal carrying material-to a degree sufficient to amalgamate the most minute particles of precious metal, when the same are acted upon by the mercuric chlorid. It is thus seen that within the shell 17 the process of electrolysis is carried out, the iron shell 17 and drum 21 being electro-positive, while the fine particles of gold, platinum, silver or the like are electro-negative, being the less soluble, whereby the metallic mercury precipitated from ,the mercuric chlorid will deposit on and .amalgamate with the'precious metals. The deposition ofthe metallic mercury occurs by voltaic coupling of any of the electro chemically excited parts ofthe interior of the iron shell 17 and drum 21 with the precious metals, therefore the toothed drum is rapidly rotated, to compel, as near as possible, every part of the passing pulp of pre cious metal containing material, including its precious metal particles, to contact with the eleotro-positive excited parts of the iron shell. As such contact may be, and usually is, instantaneous, the quantity of mercury deposited on the particles of precious metal may be comparatively small, particularly when the mercuric chlorid solution is weak. The deposition of the metallic mercury upon the particles of precious metal, as a result of the electrolysis of mercuric chlorid, as above indicated, may be substantially aided by the addition of the sulfuric acid, by reason of its greater action upon the iron material of the shell 17 or drum 21, but at the expense of the more rapid destruction of the latter, In some cases, the ores may carry, in addition to the particles of precious metals, combinations of sulfur or the'like metals, that it is not desired to save, such for instance as sulfur, arsenic, antimony, etc. The latter are readily soluble in an acid, such as sulfuric acid in suitable quantity, the ailinity of which for arsenic and antimony is much greater than for the iron of the agitating parts. In such cases, the sulfid arsenic or antimony, solutions thus obtained, if still carrying free acid, instead of contaminating the metallic mercury, tends to purify the same. The addition of the sulfuric acid, properly diluted, to the aqueous solution of mercuric. chlorid, in the tank 38,

will result in the simple mixture of the two solutions, without 'deleterious action on either. Such a mixture is regularly fed to within the shell 17, as above stated, while the pulp is being subjected to the action of the chemical solution formed of an aqueous solution of mercuric chlorid and sulfuric acid. The chemical solution and ore pulp are preferably subjected to the action of adventitious electric energy or current, the character of which is tobe determined in view of the particular'character of the material being treated. Either direct or alterthe pulp which is being violently agitated I nating current may be used,-bu t it is preferred to use a direct current having its polarity periodically reversed. As above explained, one pole ofthe source of current is connected with the drum 21 while the other pole is connected with the shell 17. Inasmuch as iron and platinum are not sus ceptible to amalgamation with mercury unalloyed with sodium in the absence of a properly-applied adventitious electric curcurrent, it is obvious that it is advantageous I quently reversed, whereby deposit metallic mercury to use such current, to recover the platinum. However, it is not. desired that the mer- 'cury should combine with the iron of the shell 17 or drum 21. The shell 17 and drum 21 are insulated from each other, as described, whereby they will alternate in polarity synchronously with a source of current,- having its" polarity periodically or freany tendency to upon the shell 17 or drum 21 will be instantl succeeded and neutralized by an equal-energetic tendency to throw any deposited metal off the same.

The suspended particles of gold and platinum, by reason of the violent agitation fthe pulp by the means hereinabove $0 magnetic effect being that said metallic particles assume a like polarity. to that .of.

vdescrl ed, and also because of the well known magnetic effect on such loose metallic particles in such a magnetic field, the said its dominating neighbor at the instant of v contiguity and consequently repellent thereto, combine with the precipitating metallic mercury,=while the exciting surfaces'of the shell 1,

and the toothed drum 21 remain practically clear of mercury or amalgam,

thus obviating the necessity of scraping off said amalgam to recover the values therefrom. The advantage of employing an alternating current or a direct current having its polarity periodically'reversed, will also be apparent by the consideration of the fact that the ores of the metals, such as gold,

platinum, silver or the like, not infrequently carry copper in -a condition capable of solution in the mercuric chlorid and sulfuric acid menstrum, before mentioned. Under the action of. electrolysis, which takes place in'the shell 17, as above stated, with the use of a direct current'passing continuously in one direction, metallic copper will be de posited on the interior of the shell 17 if versed, the copper'and mercury will. not be deposited upon the shell or drum, for any tendencyto deposit the samethereon when such as gold, and platinum, are combined the current has one polarity is repelled when the polarity of the current is reversed. a result of treating the pulp, as above explamed, the fine particles or precious metal,

or coated with the mercury, the pulp carryingthe amalgamated particles of precious metals passing through the pipe 35, and into the rotatable tubularshaft 60 to be dis-- charged Within the lower portion of the receptacle 61, which is partly filled with metallic mercury. The blades or-agitators 62 are rotated at the proper speed, whereby the pulp is continuously agitated so that the mercury coated fine. particles of the precious metal may be absorbed by the quantity of metallic mercury at the bottom of the receptacle 61 and the pulp then passes through pipe 68, to be fed into the tubular shaft 60 of the next apparatus, also containing metallic mercury. Any required number of the apparatuses containing metallic mercury may be employed, as is found advantageous.

In order to prevent the obstruction of the I flow of the pulp through the vertical .tubular shaft 60, by the lower end thereof being" submerged too deeply in the metallic mercnrywhich has a specific gravity considerably exceeding that of the pulp, the tubular shaft 60 may be vertically adjusted to move the lower end thereof toward and away from the upper surface of the metallic mercury. As the manner in whichvthe vertical shaft 60 operates has already been'described it will not be repeated. The precious metals having been thus separated from the ore pulp, and retained by the 'metallic' mercury baths in the receptacles 61' as hereinbefore described, the now barren pulp flowsout through the pipe 68 to waste.

At desired times the mercury, containing its collected amalgamated values, is drawn out from the receptacles 61 and retorted, or

otherwise treated by any of the well known or prepared processes for separating the precious metals from the metallic mercury.

Having thus described my invention, I claim 1. In apparatus of the character described, an outer shell provided with interiorly arranged-teeth and adapted to be approximately horizontally arranged, a rotatable drum mounted therein and provided near its ends with tapered portions decreasing in diameter inwardly and carrying the teeth arranged between the tapered portions to cooperate with the first named teeth, an inlet conduit leading into one end of the shell near one tapered, portion ofthe drum, and, an outlet conduit leading into the shell near 126 the other tapered portion of. the drum.

2. In apparatus of the characterdescribed, an outer shell provided with interiorly arranged spaced teeth, a rotatable drum mounted within the outer shell and carrying 130 spaced teeth cooperating with the first named teeth and having an axial bore of substantial diameter extending for the greater portion of the"length of the drum and havin its opposite end closed by apertured hea s, a shaft extending longitudinally through the outer shell and through the drum, said shaft being spaced from the walls of the axial bore, and means to ri 'dly connect the apertured heads with the aft.

3. In agparatus of the character described, an outer ell provided with interiorly arranged spaced teeth, a drive shaft extending lon tudinally through the outer shell, :3. rotata 1e drum arranged within the outer shell and provided with teeth and having an axial bore to receive the drive shaft and apertured heads closing the ends of the bore and also receiving the drive shaft, transverse elements passing through the apertured heads and drive shaft to rigidly connect the same, means to rotate the drive shaft, means to insulate the outer shell and drum, and means to connect the outer shell and drum with the opposite poles of a source of current.

In testimony whereof I aifix my signature in presence oftwo witnesses.

FREIJQERICK A. WISWELL. Witnesses:

W. A. STOCK, R. M. OYARZO.

copies at this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

